Vapor-electric device



Sept. 23, 1947.

W. E. PAKALA ET AL VAPOR ELECTRIC DEVICE Filed July 12, 1940 4Sheets-Sheet 1 v WITNESSES:

INVENTORS M7// 0? fzQvra/a Q 7 and f/gr C. M ers.

If 'M ATTORNEY Sept. 23, 1947. w. E. PAKALA ETAL 2,427,738

VAPOR ELECTRIC DEVICE Filed July 12, 1940 4 Sheets-Sheet 2 T T faway/Mum. 224 5: Maynef/z/ny Curran/7 o frga? WITNESSES: N' 7/EINfl/ENTOR/S f' I lam aka a Z and flsngyy'f Aye/:5. Z2. 6. L174 JM44ATTORNEY p 23, 1947- w. E. PAKALA EI'AL 2,427,

VAPOR ELECTRIC DEVICE Filed July 12, 1940 4 Sheets-Sheet s WITNESSES:INVENTORS ATTORNEY Sept. 23, 1947. w. E. PAKALA ETAL VAYOR ELECTRIC DEVICE Filed July 12, 1940 4 Sheets-Sheet 4 INVENTORS M /I H E ara/a andHear 6. A4/ers.

a. mm

ATTORN EY WITNESSES? 24 7% Patented Sept. 23, 1947 UNITED STATES PATENTOFFICE VAPOR-ELECTRIC DEVICE William E. Pakala, Forest Hills, and HenryC. Myers, Irwin, Pa., assignors to Westinghouse Electric Corporation,East Pittsburgh, Pa., a

corporation of Pennsylvania Application July 12, 1940, Serial No.345,096

vice, and particularly to a control system for a vapor electricconverter of the make-alive type. In the operation of make-alive typevalves, it

solai s. '(01. 175-363) Fig. is a schematic illustration showing a sim--In the illustrated embodiment of our invention 1 according to Fig. 1, analternating current circuit is necessary to periodically apply controlimpulses 5 l is connected to a direct current circuit '2 by to themake-alive electrodes in order to initiate means f a Suitabletransformer current flow the current carryingarcs in the valves.Herethrough the transformer 3 being controlled by tofore eitherauxiliary electronic valves or conmeans of Man t -d 'c pr tact deviceshave been utilized for applyin these a p ur ty of Valves 4 f themake-alive typ periodic impulses. Heretofore control impulse Each V e 4Comprises a le evacuated supplying devices have been unsatisfactoryeither tamer 5 a i g a vaporizable cathode 6, P because0f"bl1!l'iing.0.l1t of the control tubes or y u y 0 other Suitablematerialr damage to the contact elements ofthe mechani- Operating withthe cathode 5 is a suitable anode ca1devices l 1 I which may be providedwith a suitable shield 8. We have found that suitable control impulses felectmde 9 provided in cohtach can be generated by utilizing asaturablechoke i the 5 and preferably phovlded to distort the.usualalternating current wave h adJhstable mountlhg to determlhe theforms to produce suitable impulse .wave forms for lmmerslon of makeahveelectrode 9 m the application to the control electrodes. cathodematerial: bt Further, by suitably impressing a Dremagnetizg lmpulsftsfrom ing current or biasing current on the saturable a 6 source of aelfna mg Vo-tage of t e r frequency as the main alternating-currentcircuit chokes, the phase relation or time lnstant of the of the vaporelectric valves 4 and havin a r applicationof the impulse can becontrolled as A p edetermined phase with respect to said main alter- Wehas the magmwde and a e of the m nating-current' circuit I. Saidcontrol-circuit pulse! f 4 alternating current source is hereinillustrated have, 9l d fu ther'thatthe total e e y as a controltransformer ll connected to the alnecessary to m i h cathodefsliot? marbe f ternating current circuit 1. 'The' secondary 12 of l' d by the useQfisuitable e y s s ethe control transformer 1| is provided with apluvices in parallel with'the initial controlpotential. rality of phasewindings; all of which h e a It is an object of -our invention toprovide a mon'connection I3 which is connected by means control sy h ngsaturable chokes to con of a suitable circuit 14 to the cathodes 6 ofall trol the application of control potential to the of the make-alivetype valves 4. The phase ter make-alive electrodes of electric valveslminals are individuallyconnected to the several It is a further objectof our invention to promake-alive electrodes 9 and in each of theseconvide a control system in which the, phase relation nections we haveprovided a suitable non-linear of the control impulse may be-readilyadjusted: impedance-device, illustrated in the form of a It is a stillfurtherobject of our invention to saturable reactor, choke-coil, orinductance-deprovide a control system requiring a minimum vice, having awinding l5 associated'with a mag amount of control energy. 40 netic coreI6, preferably of a high permeability Other objects and advantages ofour invention material having a sharp saturation point. While will beapparent from the following detailed deany suitable magnetic materialmay be utilized, scription taken in conjunction it the accomwe prefer toutilize a. nickel-iron alloy such as panying drawings,in which:disclosed in Yensen Patent No. 1,807,021. 1

Figure 1 is a schematic illustration of a control Connected in seriesbetween the phase e al system according to our invention, and themake-alive electrode 9 is a suitableuni- Fig. 2 is a diagrammaticillustration of t o directional conductor 0r asymmetrically conductrentand flux variations in the saturable choke s device which may be eithera copp OXide according to our invention, rectifier, a glow tube or anyother suitable de- Fig. 3 is a diagrammatic illustration showing vice.The series rectifier I! is utilized to prevent the wave forms ofcurrent, voltage and flux in inverse currents from flowing to themake-alive the saturable choke. electrode 9 which might damage themake-alive Fig. 4 is a schematic illustration similar to device or evencause improper operation during Fig. 1, showing a modification accordingto our I the inverse half cycle. A suitable unidirectional invention,and v or asymme cal conducting device I8 is then placed in shunt acrossthe make-alive electrode 9 and the unidirectional conductor IT todissipate the inverse energy to prevent the cumulative'unidirectionalsaturation or the magnetic core of the 2|. Preferably, suitableresistance devices 22 are provided for permitting adjustment of thedirect current in the auxiliary winding 20.

In series with the auxiliary winding 20 we have provided large capacitychokes 23 to damp out of the direct current circuit any surges arisingin the alternating current circuit,

Because of the high permeability characteristic of the core IS-of thesaturable choke, it is desirable to maintain a premagnetization of thecore so that when the current is flowing to the makealive electrode, thecurrent plus the permagnetization will saturate the saturable core l8 sothat a current impulse of considerable magnitude will flow through thesaturable choke, while during the inverse potential the magnetizingcurrent will not be sufllcient to saturate the choke so that the inversecurrent will be kept at a minimum.

In the operation of the device of Fig. 1 according to our invention, thecontrol transformer. supplies a substantiallysymmetrical alternatingvoltage of equal positive and negative half-waves, that is, havingsubstantially no direct-current component. and having a substantiallysinusoidal wave form 25 (Fig. 3) which produces a, magnetizing current28, establishing a flux 21 in the saturable reactor. At the same timethe direct cur- .rent premagnetization establishes a permanent bias fluxA (Fig. 2) in the saturable core, and thesize of the core is such that,as the altematingcurrent component of the flux increases, at anintermediate portion of each p sitive and negative half-wave of thealternating-current wave the total flux reaches the saturation point B,

whereby a discontinuity in the saturation-curve of the induction-deviceis obtained at said portion of each positive and negative half-wave orimpulse, so that the magnetizing current in-l creases at a rapidrate,'producing a peaked curl rent-impulse of considerably less thanhalf-cycle duration. This high current impulse is transmitted to themake-alive electrode 9 by the series connected unidirectional conductorII. In the inverse half cycle, however, the current is not/sufficient toovercome the premagnetizing eflect sufilcient to reach the saturationpoint so that the inverse current never exceeds the normal magnetizingcurrent C of the choke. This inverse current is bypassed around themake-alive electrode 8 by means of the unidirectional conductor l8. Byadjusting the amount of premagnetization the additional flux required toproduce saturation can be changed and thus the phase relation of theimpulse can be shifted as well as the time duration of the impulse.

For purposes of illustration, in Fig. 1, we have shown individualadjustments'22 for each of the premagnetizing windings 20. However, itis apparent that in normal operation all of these premagnetizingwindings 20 will be connected to- 4 gether and controlled by a singleadjustment 2!, as shown in Fig. 4.

The embodiment according to Fig. 4 differs from that of Fig. 1 in thatsuitable energy storing devices herein illustrated as capacitors 30 areconnected in parallel with the phase windings, and suitable impedances 3I herein shown as linear or non-saturating reactors, are utilized tocontrol the rate of flow of current from the phase windings into theenergy storing devices 30. At the instant when the magnetizing currentproduces a flux which exceeds the saturation point of the core, theenergy storing devices will discharge,

producing an impulses of steeper wave front and narrower angle than thatsecured without the aid of the energy storing devices. A steep wavefrontof the impressed voltage-wave sending current through the reactor II andthe make-alive electrode 9 is particularly useful, in the makealivecontrol of the rectifier-valves 4, because the condition of themake-alive electrode changes, from time to time, thus causing themagnetizing current of the serially connected reactor 15 to vary. If thewave-fronts of the successive halfcycles of this magnetizing-current aresteep, the point at which ignition occurs will occur at very nearly thesame time-phase in each half-cycle, regardless of the condition of themake-alive electrode,'thus making the operation of the vaporelectricvalves 4 more uniform.

Inthe modification according to Fig. 5, we have shown a simplifiedembodiment of our device which is particularly suitable to single-phaseconverters. However, a plurality of these devices connected todiametrically opposite phase terminals may be utilized for controllingpolyphase systems. In order to simplify the construction the chokes oftwo diametrically opposite phases have been combined into a single threelegged choke I6 which utilizes a single premagnetizing or phase shiftingwinding 20', thus conserving both material and space. As shown in Fig.5, the

alternating-current winding I5 of the saturable choke-coil orinductance-device is divided into two equal parts disposed on the twoouter legs of the three-legged core l6, so that the alternatingcurrentflux is circulated in a closed magnetic path of such dimensions as to besaturable under the operating conditions of the device, in the mannerpreviously explained. The direct-current winding 10' is disposed on thecentral leg of the core ll, so that its flux divides between the twoouter legs, so that the direct-current winding 20' is non-inductivelyrelated to the alternating-current windings ii of the three-legged corell".

While for purposes of illustration, w have shown and described specificmodifications according to our invention, it will be apparent that manychanges and modifications can be made therein without departing from thetrue spirit of our invention or the scope of the appended claims. Thebroader aspects of the general combination using a saturable reactor inthe makealive control are covered by a companion-application, Serial No.346,287, filed July 19, 1940, of William E, Pakala.

We claim as our invention:

1. A make-alive control-system, comprising a valve-device; analternating-current source; a non-linear impedance; a linear impedance;a capacitor; a series asymmetrically conducing device; a shuntingasymmetrically conducting device; a make-alive circuit including, inseriescircuit relation, said alternating-current source, said linearimpedance, said non-linear impedance, Said series asymmetricallyconducting device, and a make-alive electrode of said valvedevice,whereby unidirectional-current impulses of one polarity are delivered,through said'series asymmetrically. conducting device, to saidmakealiveelectrode; a shunting circuit, including said shuntingasymmetrically conducting device, connected in shunt-circuit relationaround said make alive electrode and said series asymmetricallyconducting device, whereby a path is provided for unidirectional-currentimpulses of theother polarity; and a shunting circuit, including saidcapacitor, connected in shunt-circuit relation around both saidalternatingcurrent source and said linear impedance, so as to cooperatewith said alternating-current source in supplying energy to saidnon-linear impedance and to said make-alive electrode and meansfor-varying said non-linear impedance.

2, A make-alive control-system, comprising a valve-device; analternating-current source; an inductance-device having a saturablecore; a capacitor; an auxiliary impedance-device; a, seriesasymmetrically conducting device; a shunting asymmetrically conductingdevice; circuit-means, serially including said alternating-currentsource and said auxiliary impedance-device, for impressing upon saidcapacitor an alternating voltage having substantially equal positive andnegative impulses; circuit-means, including said capacitor, forimpressing upon said inductance-device an alternating voltage havingsubstantially equal positive and'negative impulses, in such magnitude asto saturate the inductance-device at a portion of each of the positiveand negative impulses, whereby a discontinuity in the saturation-curveof the inductance-device is obtained at said portion of each positiveand negative impulse; makealive circuit-means, including said seriesasymmetrically conducting device, for utilizing said inductance-deviceto cause peaked positive currentimpulses to be supplied to a make-aliveelectrode of said valve-device; and a shunting circuit, ineluding saidshunting asymmetrically conducting device, connected in shunt-circuitrelation around said make-alive electrode and said series asymmetricallyconducting device, whereby a path is provided for the peaked negativecurrent-impulses, an auxiliary winding on said inductancedevice andvariable means connected thereto for impressing direct current on saidauxiliary windins ii. A make=alive system comprising analternating-current source; a saturable reactor; av

capacitor; a series asymmetrically conducting.

device; a shunting asymmetrically conducting device; a currentsupplyingcircuit including, in series circuit relation, said alternating-currentsource, said saturable reactor, said series asymmetrically conducingdevice, and a load-device, whereby unidirectional-current impulses ofone polarity are delivered, through said series asymmetricallyconducting device, to said load-device; a shunting circuit, includingsaid shunting asymmetrically conducting device, connected inshuntcircuit relation around said load-device and said seriesasymmetrically conducting device, whereby a path is provided forunidirectional-current impulses of the other polarity; and a shuntingcircuit, including-said capacitor, connected in shuntcircuit relationaround said alternating-current source, so as to cooperate with saidalternatingcurrent source in supplying energy to said saturable reactorand to said load-device, and means 6 for varying the saturation point ofsaid saturable reactor.

4. A make-alive system comprising an alternating-current source; aninductance-device having a saturable core; acapacitor; a seriesasymmetrically conducting device; a shunting asymmetrically conductingdevice; circuit-means connecting said altemating-current source to saidcapacitor, for impressing upon said capacitor an alternating voltagehaving substantially equal positive and negative impulses;circuit-means, including said capacitor, for impressing upon saidinductance-device an alternating voltage having substantially equalpositive and negative impulses, in such magnitude as to saturate theinductancedevice at a portion of each of the positive and negativeimpulses, whereby a discontinuity in the saturation-curve of theinductance-device is obtained at said portion of each positive andnegative impulse; a current-supplying circuit-means, including saidseries asymmetrically conducting device connecting saidinductance-device to a load-device; for utilizing said inductance-deviceto cause peaked positive current-impulses to be supplied to theload-device; and a shunting circuit, including said shuntingasymmetrically conducting device, connected in shunt-circuit relationaround said load-device and said series asymmetrically conductingdevice, whereby a path is provided for the peaked negativecurrent-impulses, and means for varying the saturation point of saidinductance-device.

5. In combination: an alternating-current source; an inductance-deviceincluding a threelegged magnetizable core having an outer-leg closedmagnetic path of such dimensions as to be saturable under the operatingconditions of the device, an alternating-current windingmeans dividedinto two equal parts on said outer legs, and asubstantiallynon-inductively related direct-current winding-means on thecentral leg of said core; a current-supplying circuit-means, includingsaid alternating-current source and an alternating-current winding-meansof said inductance-device, for supplying a load-device with a,succession of controlled unidirectional peaked current-impulses ofconsiderably less than halfcycle duration; and variable direct-currenteX" citing-means for the direct-current windingmeans of said impedancedevice.

6. In combination, an electric valve means having a control member, a,source of alternating current, and an excitation circuit fortransmitting an impulse of current to said control mem ber comprising a.capacitance, 'a saturable nonlinear inductive reactance arranged tosaturate within the normal range of operating-current of said excitationcircuit and connected! to said capacitance for effecting discharge ofsaid capacitance and a linear inductive reactance connected between saidsource and said capacitance and in the charging circuit of saidcapacitance for limiting the amount of current derived from said sourceupon discharge of said capacitance.

'7. In combination, an electric valve means having a control member, asource of alternating current, and an excitation circuit fortransmitting an impulse of current to said control member comprising acapacitance connected to be charged from said source, an impedanceelement, a saturable inductive reactance connected between saidcapacitance and said impedance element for abruptly discharging saidcapacitance 7 through said impedance element and a linear inductivereactance connected between said source and said capacitance forlimiting the amount of current derived from said source when theinductive reactance of the saturable reactance abrupt- 1y decreases.

8. In combination, an alternating current supply circuit, a loadcircuit, a control circuit for transmitting an impulse of current tosaid load circuit comprising a capacitance, a saturable nonlinearinductive reactance arranged to saturate within the normal range ofoperating current of said load circuit, means connecting said reactanceand said load circuit in series and to said capacitance to establish adischarge circuit therefor, and means including a substantially linearinductive reactance connecting said capacitance with said source toprovide a circuit for the transfer of alternating'current energy fromsaid source to said capacitance and to offer substantial impedancebetween said source and said capacitance during discharge of saidcapacitance.

WILLIAM E. PAKALA. HENRY C. MYERS.

REFERENCES CITED The following references are of record in the file ofthis patent:

, UNITED STATES PATENTS Number Name Date 1,986,617 Bedford Jan. 1, 19351,990,366 Bivens Feb. 5, 1935 2,103,779 Gilliksen Dec. 28, 19372,148,049 Kern Feb. 21, 1939 2,010,571 Wagner Aug. 6, 1935 2,130,902Rose Sept. 20, 1938 2,165,911 Slepian July 11, 1939 2,182,647 SlepianDec. 5, 1939 2,222,620 Klemperer Nov. 26, 1940 2,259,329 Slepian et a1Oct. 14, 1941 2,259,295 Cox et a1. Oct. 14, 1941 2,259,293 Cox et alOct. 14, 1941 1,994,907, Dawson Mar. 19, 1935 2,300,872 Cox Nov. 3, 19422,292,034 Bahls Aug. 4,1942 2,291,092 Cox July 28, 1942 2,248,600Alexanderson et a1. July 8, 1941

